You need to create a rule for Mod Rewrite. How?

Question

PHP

There is a type rule
RewriteRule ^auth$ index.php?action=auth&t=3 [L]
in index.php: the include "pages/auth.php";
link looks like localhost/auth
I'm processing data (I screwed authorization through VKontakte), then there is a redirect to localhost/auth?code=f2e5e7f27b266f1261 (the code parameter is 18-digit alphanumeric). This parameter is not passed to either $_GET or $_REQUEST. Further, in my script, a check is in progress for the presence of code, but the variable is not defined - the script does not work. Help write a Mod Rewrite rule for my situation.
PS If you do not use the mod, then everything works (links with php pages)

Answer 1

RewriteCond %{QUERY_STRING} (.*)
RewriteRule ^auth$ index.php?action=auth&t=3&%1 [L]